1. Field of the Invention
The present invention is related to an image processing apparatus, an image processing method, and an image processing program for investigating states of cardiac motion.
2. Description of the Related Art
The heart pumps out blood, which is temporarily stored therein, to circulate the blood throughout the body by periodic contracting and expanding motions of myocardia. If circulation of blood deteriorates due to incomplete cardiac motion, immunity decreases, which is a factor that may cause various diseases.
In this respect, various methods for analyzing and evaluating states of cardiac motion have been proposed. For example, there is a known technique in which amounts of myocardial wall motion and changes in myocardial wall thickness are measured from a plurality of three dimensional images of a heart by imaging in temporal series, then the state of cardiac motion is evaluated employing the results of measurement. In addition, there is another known technique that evaluates the state of cardiac motion by a value obtained by dividing an amount of blood pumped by a single heartbeat (ejection amount) by the volume of a left ventricle (refer to Japanese Unexamined Patent Publication No. 9 (1997)-238932).
In hearts, contracting/expanding motions are not performed by all of the myocardia simultaneously, and the timings of contractions/expansions differ among parts of the heart. Particularly, a twisting motion of a specific pattern generated by the slight shifts in contraction timings enables efficient circulation of blood throughout the body. However, if changes occur in the contraction timings due to myocardial infarction or the like, efficient circulation of blood is precluded, which is a problem. Therefore there is demand to analyze and evaluate the contraction timings of myocardia at a plurality of positions of the heart.
However, the aforementioned conventional techniques do not focus on the shifts in the contraction timings of different parts of myocardia, and it cannot be said that they provide a solution to the above needs regarding analysis of cardiac motion.